By Ty Higgins, Ohio Ag Net
It only takes a few clicks on the remote to find plenty of crime scene investigators tracking down criminal on television, but the use of some of the same televised crime solving technology in crop fields is a little less common.
USDA researchers are now using a forensic crime tool to identify insects that are natural predators to crop pests. Mike Greenstone is an entomologist with the Agricultural Research Service and he said that researchers are using Preliminary Change Reaction, a tool that is used to identify DNA in bodily fluids or saliva from perpetrators of crimes. This same tool is now also being used to study DNA barcoding of natural predators of pests, such as ladybugs, in crop fields. Greenstone said this can be a useful tool for farmers.
“If a farmer sees predators in the field he should try to avoid killing them or he should try to make things more hospitable for them in the field,” Greenstone said. “In particular, try to avoid using broad spectrum pesticides that kill not just the pest, but every other insect in the field or delay spraying until a later date if that is possible.”
Most recently Greenstone said he was using this Preliminary Change Reaction technique on the Colorado potato beetle, which is a very devastating pest. He says ladybugs and other true predatory bugs feed on that beetle. Before that, Greenstone worked on aphid pests, but he has used barcoding in other ways too.
“Barcoding is used as a diagnostic tool,” Greenstone said. “It is really important to have a diagnostic tool, especially if you have an insect that is hard to identify. Think about the immature forms of predatory insects. Everybody knows what ladybugs look like, but not everyone knows what the immatures look like. The immatures of different species of ladybugs often look quite a bit alike.”
A DNA barcode for the adult is the same as the DNA barcode for the immature that cannot be identified visually. This can help determine the importance of the immature insects as well as the adults.